Three-dimensional data encoding method, three-dimensional data decoding method, three-dimensional data encoding device, and three-dimensional data decoding device

Abstract

A three-dimensional data encoding method including: generating a layered structure including one or more layers by hierarchically arranging three-dimensional points each having an attribute information item; encoding the attribute information item of each of the three-dimensional points using the layered structure; and generating a first bitstream including the attribute information item encoded and an identification information item indicating whether the three-dimensional points used in the hierarchical arranging are re-ordered in Morton order before the hierarchical arranging.

What is claimed is: 
     
         1 . A three-dimensional data encoding method comprising:
 generating a layered structure including one or more layers by hierarchically arranging three-dimensional points each having an attribute information item;   encoding the attribute information item of each of the three-dimensional points using the layered structure; and   generating a first bitstream including the attribute information item encoded and an identification information item indicating whether the three-dimensional points are processed in an order of input.   
     
     
         2 . The three-dimensional data encoding method according to  claim 1 ,
 wherein when the identification information item indicates that the three-dimensional points are not processed in an order of input, in the generating of the layered structure, the three-dimensional points are not processed in an order of input.   
     
     
         3 . The three-dimensional data encoding method according to  claim 1 ,
 wherein when the identification information item indicates that the three-dimensional points are processed in an order of input, in the generating of the layered structure, the three-dimensional points are processed in an order of input.   
     
     
         4 . The three-dimensional data encoding method according to  claim 1 ,
 wherein the layered structure includes one layer.   
     
     
         5 . The three-dimensional data encoding method according to  claim 1 ,
 wherein the layered structure includes two or more layers, and   the three-dimensional points are classified into the two or more layers in such a way that a distance between three-dimensional points belonging to a higher layer is longer than a distance between three-dimensional points belonging to a lower layer.   
     
     
         6 . The three-dimensional data encoding method according to  claim 1 , further comprising:
 generating a second bitstream when the layered structure includes two or more layers, the second bitstream including the attribute information item encoded and a layer information item used in generating the layered structure including the layers.   
     
     
         7 . The three-dimensional data encoding method according to  claim 6 ,
 wherein the second bitstream does not include the identification information item.   
     
     
         8 . A three-dimensional data decoding method comprising:
 obtaining a bitstream including an attribute information item encoded based on three-dimensional points arranged hierarchically to form a layered structure including one or more layers; and   decoding the attribute information item encoded, based on whether the bitstream includes an identification information item indicating whether the three-dimensional points are processed in an order of input.   
     
     
         9 . The three-dimensional data decoding method according to  claim 8 ,
 wherein in the decoding, in a case where the bitstream is a first bitstream including the identification information item,   when the identification information item indicates that the three-dimensional points are not processed in an order of input, the layered structure is generated by hierarchically arranging the three-dimensional points without processing the three-dimensional points in an order of input, and the attribute information item encoded is decoded using the layered structure.   
     
     
         10 . The three-dimensional data decoding method according to  claim 8 ,
 wherein in the decoding, in a case where the bitstream is a first bitstream including the identification information item,   when the identification information item indicates that the three-dimensional points are processed in an order of input, the three-dimensional points are processed in an order of input, the layered structure is generated by hierarchically arranging the three-dimensional points processed in an order of input, and the attribute information item encoded is decoded using the layered structure generated.   
     
     
         11 . The three-dimensional data decoding method according to  claim 9 ,
 wherein the first bitstream indicates that a layered structure including one layer is generated.   
     
     
         12 . The three-dimensional data decoding method according to  claim 8 ,
 wherein the layered structure includes two or more layers, and   the three-dimensional points are classified into the two or more layers in such a way that a distance between three-dimensional points belonging to a higher layer is longer than a distance between three-dimensional points belonging to a lower layer.   
     
     
         13 . The three-dimensional data decoding method according to  claim 8 ,
 wherein in the decoding, in a case where the layered structure includes two or more layers, and the bitstream is a second bitstream including a layer information item used in generating a layered structure including layers, the layered structure including the layers is generated by hierarchically arranging the three-dimensional points using the layer information item, and the attribute information item encoded is decoded using the layered structure generated.   
     
     
         14 . The three-dimensional data decoding method according to  claim 13 ,
 wherein the second bitstream does not include the identification information item.   
     
     
         15 . A three-dimensional data encoding device comprising:
 a processor; and   memory,   wherein using the memory, the processor:
 generates a layered structure including one or more layers by hierarchically arranging three-dimensional points each having an attribute information item; 
 encodes the attribute information item of each of the three-dimensional points using the layered structure; and 
 generates a first bitstream including the attribute information item encoded and an identification information item indicating whether the three-dimensional points are processed in an order of input. 
   
     
     
         16 . A three-dimensional data decoding device comprising:
 a processor; and   memory,   wherein using the memory, the processor:
 obtains a bitstream including an attribute information item encoded based on three-dimensional points arranged hierarchically to form a layered structure including one or more layers; and 
 decodes the attribute information item encoded, based on whether the bitstream includes an identification information item indicating whether the three-dimensional points are processed in an order of input.